Lancashire Bats

The diversity of bats tends to decrease the further North you
go in Britain, so not all British bat species are found in our area with only
eight that are permanent resident and two that were either recorded in the
past and one that may have been transported from another area. The
table on this page shows which of the species occur in Lancashire.
and more information is given below on some of the more common
bats.

Much of the early work of The Michael Birt Consultancy was
concerned with Pipistrelle bats. As a
result many of our records are of Pipistrelle which are numerous in Lancashire
and are found throughout the county.

Of course, it has recently been discovered that Pipistrelles
are two separate species. The main distinguishing feature is the
peak frequency at which they call - either around 45kHz (now known
as the Common Pipistrelle) or 55kHz (the Soprano Pipistrelle).
There are some suspected minor differences in appearance, but by
far the easiest way to identify them is by the use of a bat
detector.

When the news broke about the discovery of the two species it
was widely proclaimed that most Lancashire's bats were of the 45kHz
type while 55kHz bats were commoner across the Pennines. Whilst
there may be some truth in this, 55kHz bats have been found at
many sites across the county - a recent survey of farm woodlands
by MAFF Central
Science Laboratory found 55kHz Pipistrelle at a third of
sites, whereas 45kHz bats were found in nearly all the woodlands.

The brown long-eared bat (Plecotus auritus) is probably the most common
Lancashire species after the Pipistrelle. Yet, for the average participant in a public bat
walk, it is a species which they are fairly unlikely to see.

As well as catching insects in free flight, brown long-eared
are gleaners, picking insects off the foliage. Thus, they often
fly against a background of dark trees, rather than against the
sky, making them almost invisible. Their echolocation calls are
extremely quiet, being only detectable when the bat is a few feet
away, even in an enclosed space. Even where roosts are known, it
is perfectly possible for the bats to slip out in the evening
unseen. Only the lucky observer, catching a rare glimpse of the
species flying away from a cluttered background, will see its
large ears outlined against the sky.

Because of the difficulty of observing the species in the wild, especially
with a bat detector, there are far fewer records of brown long-eared bats in
Lancashire than of Pipistrelles.
It is also impossible to separate the species from the grey
long-eared bat, except in the hand, so although it is thought
that the grey long-eared is very rare and confined to southern
England, there must always be a doubt as to the identity of a
long-eared bat in free flight. Most records, consequently, are of
bats roosting in houses.

A number of roosts have been recorded over the years in
locations around the Rossendale Area and more so in the Haslingden Areas of the
Rossendale valley

We have a only scattering of records of Noctule across the
county, but they do suggest a widespread distribution. The reason
for the dearth of records is that until recently we have gathered
few bat records from trees, the preferred roost site of Noctule bats.

One or two roosts are known in the county. A couple of years
ago a roost in an ash tree came to light and as been used by Noctule over the
last 15 years

Noctule bats preference for tree roosts dictates its need for
mature and over mature trees. Consequently it is perhaps
surprising that Noctule appear to be fairly commonly encountered
hunting over the largely treeless areas. They are
undoubtedly attracted by the quantities of insects to be found
over this terrain

Daubenton's bats are easy to see and identify, skimming
just above the surface of the water. They are regularly watched
at places over slow running parts of the Irwell, Limy and Whitewell rivers along
with many other sites in Lancashire.

Many Daubenton's roosts are in bridges, canal tunnels and the
like, from which they may fly up to 10km to feed. It can,
therefore, be quite a challenge to find those roosts which are in
tree holes nowhere near the water. Some roosts, mainly in bridges
or old buildings, are known us and these have been the
subject of regular monitoring over the years.

In winter, Daubenton's is one of the species known to
hibernate underground. They are often solitary, but it is
possible to find small groups in one cave. However, they
are usually tucked in difficult to spot places such as tight
crevices, or even among the loose scree and rock on the cave
floor.

Rather like Whiskered/Brandt's, records of Natterer's bats are widely but
thinly distributed. These records undoubtedly under-represent the
distribution of this species which can be quite difficult to find
in the wild.

The echolocation calls as heard on a bat detector are rather like those
of a Daubenton's bat, making identification in flight very hard. There are
subtle differences in the calls, but while Daubenton's can be identified by
listening and observing its hunting method over water, the Natterer's
feeding behaviour in its preferred woodland edge habitat is less obvious.

A few Natterer's roosts are known and some have been established for many
years.

In hibernation Natterer's bats are mostly found singly, often near cave
entrances, where they seem to prefer the cool conditions.

Only in 1970 were Whiskered and Brandt's bats separated into two separate
species. Therefore, it is not possible to establish the correct identity of
bats previously recorded as Whiskered bats unless a specimen is available.
Even since 1970, many records have failed to distinguish the exact species
in view of the particular difficulties involved in separating these two
species. In a few cases (usually roosts in buildings) it has is possible to
confirm the exact identity of the species by careful examination of a
specimen in the hand.

These species appear to be widely but thinly distributed across the
county. Whilst they are certainly nowhere near as common as species such as
the Brown long-eared bat, they are probably more widespread than is realized.
In common with many Myotis bats they cannot be confidently identified in
flight using a bat detector and there are still some disagreements among
bat workers as to the identity of some specimens, even in the hand.

Only in 1970 were Whiskered and Brandt's bats separated into two separate
species. Therefore, it is not possible to establish the correct identity of
bats previously recorded as Whiskered bats unless a specimen is available.
Even since 1970, many records have failed to distinguish the exact species
in view of the particular difficulties involved in separating these two
species. In a few cases (usually roosts in buildings) it has is possible to
confirm the exact identity of the species by careful examination of a
specimen in the hand.

These species appear to be widely but thinly distributed across the
county. Whilst they are certainly nowhere near as common as species such as
the Brown long-eared bat, they are probably more widespread than is realized.
In common with many Myotis bats they cannot be confidently identified in
flight using a bat detector and there are still some disagreements among
bat workers as to the identity of some specimens, even in the hand.

Leisler's bat is related to the Noctule, but is a smaller species which
tends to fly rather lower - around treetop level instead of way above the
treetops.

Although fairly widely distributed in England, its distribution appears to
be rather patchy. In some places it is apparently quite common. We have only one
record in the Blackburn and this may have come from afar as it was found amongst
timber in a haulage contractors yard

Given the presence of Leisler's bat in neighbouring counties it seems
likely that this species is present, although probably in very low numbers.
Hopefully, the increased interest in bats and growing expertise in the use of
bat detectors and the interpretation of the sounds heard on them will soon
enable us to confirm this species on the Counties list

Although everywhere rare, recent bat detector work in other parts of
England has revealed hitherto overlooked Barbastelles. It would be very
worthwhile for The Michael Birt Consultancy to organize a search for this
species in Lancashire over the coming summers in an attempt to
establish if it is present.

In the British Isles this species is now more or less confined to parts
of south-west England, Wales and Ireland. Like its larger relative, the
Greater horseshoe bat, it often feeds on insects associated with animal
dung, so it would not be expected to be widespread in the mainly arable
landscape of eastern England. However, there was once an outlying population
in Lancashire and North Yorkshire